Appendix 8 - 23 81 23.00 20 - CRAC Units.docx

UNCLASSIFIED – FOR OFFICIAL USE ONLY

Section 23 81 23.00 20:

Computer Room Air Conditioning Units DISA Facilities Engineering Circular Attachment 23-03

Effective Date: 02 July 2019

GENERAL

Scope This Section covers the technical requirements for computer room air conditioning (CRAC) units.

SUBMITTALS

DISA (Defense Information Systems Agency, Facilities Engineering Denver) approval is required for all submittals. Submit the following in accordance with Section 01 33 00, Submittal Procedures:

SD-03 Product Data Equipment and Performance Data.

Space Temperature Control System.

Filters.

SD-05 Design Data ISC Rating Calculations.

Seismic Performance Calculations.

SD-08 Manufacturer’s Instructions Manufacturer’s Safety Data Sheets Installation Manual for Each Component.

SD-10 Operation and Maintenance (O&M) Data Operation and Maintenance Manuals.

Training Plan.

Training Outline.

Training Content.

Warranty.

SD-11 Closeout Submittals Shop Drawings.

Training Completion.

MAINTENANCE MATERIAL SUBMITTALS

Provide extra materials that match products installed and that are packaged with protective covering for storage and identification with labels describing contents.

Spare Parts Provide spare parts for each manufacturer model installed.

For each type of unit installed under this Contract, provide one of each of the following:

Motor: Provide manufacturer specified motor.

Compressor: One manufacturer specified compressor for each type/size of CRAC installed.

Fuses: 1 set of unit specific fuses.

Communications Cards: Provide manufacturer communications cards that match all cards provided as part of the unit installed.

Control Panel: Provide manufacturer control panel of same model installed on unit.

Filters: Provide one complete spare filter bank set.

QUALITY CONTROL

Service Support Support the equipment items by service organizations. Submit a certified list of qualified permanent service organizations for support of the equipment which includes their addresses and qualifications. Provide service organizations that are able to render satisfactory service to the equipment on a regular and emergency basis during the warranty period of Contract.

Equipment must be supported by a service organization that is, in the opinion of the Contracting Officer, reasonably convenient to the site.

DELIVERY, STORAGE, AND HANDLING

Seal openings after manufacturing and inspection, until ready for installation.

Carefully handle, store, and protect equipment and materials to prevent damage before and during installation in accordance with manufacturer's recommendations, and as approved by the Contracting Officer. Do not subject equipment and materials to shock. Replace damaged or defective items. Protect all instruments and equipment from the weather, humidity and temperature variation; and dirt, dust, or other contaminants.

Deliver equipment to an inside location in the facility. Provide all necessary equipment and lifts to receive and move the delivered equipment. Coordinate inside delivery with the Government 30 days prior to shipping. Generally, the equipment is expected to be placed in its final location the day of delivery. If onsite storage is required, coordinate interim indoor storage requirements and location with the Government as soon as possible. Ensure onsite storage conditions meet the minimum requirements by the manufacturer to ensure warranty coverage. Provide physical installation to the final location inside the facility.

A Manufacturer’s Safety Data Sheet in accordance with 29 CFR 1910.1200 (g) must accompany each chemical delivered for use in pipe installation. At a minimum, this includes all inhibitors and refrigerants.

PROJECT/SITE CONDITIONS

Environmental Requirements Meet or exceed filter media efficiency as tested in accordance with ASHRAE 52.2.

WARRANTY

Provide a one-year, onsite, parts and labor manufacturer warranty, in writing, against defects in material and workmanship for 12 months after substantial project completion at no additional cost to the Government. The manufacturer agrees to repair or replace components that fail in materials or workmanship. Warranty must include all labor, travel, material, and related expenses to restore system and/or components from failures through the warranty period. Warranty must provide startup, maintenance, and emergency call back to ensure dependable operation throughout the warranty period.

PRODUCTS

SYSTEM DESCRIPTION

Provide new computer room air conditioning (CRAC) units complete and ready for operation.

Performance Requirements Seismic Performance Units must withstand the effects of a seismic event. Provide all necessary bracing and supports to meet requirements for installation for seismic zone III. Provide seismic performance calculations to confirm the installation meets the seismic requirement.

The term “withstand” means “the unit remains in place without separation of any parts when subject to the seismic forces specified and remain fully operational after the seismic event.”

System Air Leakage Seal unit to prevent air leakage at the raised floor penetrations.

EQUIPMENT

Standard Products Provide materials and equipment which are the standard products of a manufacturer regularly engaged in the manufacture of such products which are of equal material, design and workmanship. Products must meet the following:

Satisfactorily used in commercial or industrial facilities for at least 2 years prior to bid opening, including applications of equipment and materials under similar circumstances and of similar size. Products having less than a 2 year field service record are acceptable if a certified record of satisfactory field operation for at least 6000 hours, exclusive of the manufacturer's factory or laboratory tests, is shown.

Available for purchase in the commercial market through advertisements, manufacturer’s catalogs, or brochures for at least 2 years prior to bid opening.

Single manufacturer when two or more items of the same class of equipment are required.

Supported by a local service organization.

Computer Room Air Conditioning (CRAC) Units Equipment must comply with ASHRAE STD 15 & 34. Provide self-contained units, designed, factory assembled, and factory tested. Unit must be listed in UL Elec Equip Dir or ETL DLP for computer room application. Equipment must have a minimum sensible coefficient of performance (SCOP127) as defined by ASHRAE STD 90.1 IP Section 6 and ASHRAE STD 127.

Contractor must coordinate with unit manufacturer to provide units with sequential serial numbers where more than one unit is installed as part of the Contract.

Cabinet and Frame Unit Cabinet Unit frame must be minimum 14 gauge welded steel tubes or steel angles and millgalvanized or coated with an epoxy finish, or an approved manufacturer's standard finish, if equivalent. Maximum system height is 84 inches however, Contractor is responsible for coordinating maximum height with final unit install location when facilities have height clearances less than 84 inches.

Exterior panels must be furniture grade steel sheet, minimum of 20 gauge, with a powder-coated or corrosion-inhibiting epoxy finish. Finish color must be Charcoal.

Provide removable panel for access to controls without interrupting airflow. Panels must be gasketed to prevent air leakage under system operating pressure and removable for service access using simple, commonly available tools. Proprietary tools are not acceptable. Assemble condensate pans using a minimum 22 gauge Type 304 stainless steel, non-corroding, double-sloped, removable, and pipe to drain.

Manufacturer’s standard cabinet materials and finishes will be acceptable if considered equivalent to the above requirements by the Contracting Officer.

Cabinet Interiors Sound Attenuation Provide a factory-installed sound attenuation system in the interior of the unit cabinet.

Provide one inch of 1 1/2 pound per cubic foot neoprenecoated fiberglass insulation on interior of cabinet panels. Provide insulation with 100% adhesive coverage and both the insulation and the adhesive must conform to NFPA 90A.

Manufacturer’s standard interior cabinet sound attenuation materials and finished will be acceptable if considered equivalent to the above requirements by the Contracting Officer.

Fan Section The fans must meet the following requirements:

Plug/plenum type.

Single inlet.

Dynamically balanced.

Direct drive, electronically commutated.

Variable speed.

Located to draw air over the entire coil and ensure even air distribution and maximum coil performance.

Speed modulates to maintain under floor pressure.

Cooling Coil Provide AHRI 410 coils and slope for drainage. Assemble coil of seamless copper tubes with plate aluminum fins. Use a low sensible heat ratio for more moisture removal. Each coil, in the production process, must be individually tested at 320 psi with compressed air under water and verified to be air tight. Create a stainless steel condensate drain pan with nonferrous connections and internal trap.

Condensate Pump Cooling Coil Condensate Pump Unit must be a packaged unit including a corrosion-resistant pump, plastic tank with cover, and automatic controls. Include factory installed check valve and integral float switch. Pump shall meet the minimum flow requirements of the CRAC manufacturer’s recommendations and provide enough feet of head to reach the nearest condensate drain.

Filters Provide UL listed 4 inches thick deep pleated fiberglass throwaway type filters. Provide filtration media with a Minimum Efficiency Reporting Value (MERV) of 8 as determined by ASHRAE 52.2. Provide one complete spare filter bank set for installation prior to final acceptance testing covered in Part 3 of this section.

Refrigeration System Provide compressors complete with vibration isolation, suction and discharge service valves, high and low pressure safety switches, and built-in overload protection. Provide refrigeration circuits including hot gas mufflers, liquid-line filter-drier, refrigerant sight glass and moisture indicator, externally equalized expansion valve, and liquid-line solenoid valve factory connected with refrigeration copper tubing. System refrigerant must comply with requirements defined by U.S. EPA Section 608 and Significant New Alternatives Policy (SNAP).

Compressors Provide digital scroll compressors with a variable capacity operation capability. Compressor solenoid valve must unload the compressor and allow for variable capacity operation. The compressor must be suction gas cooled motor, vibration isolators, thermal overloads, automatic reset high pressure switch with lockout after three failures, rotalock service valves, pump down low pressure transducer, suction line strainer, and a maximum operating speed of 3500 RPM. Consult factory for 575V availability.

Refrigerant Tubing Field installed refrigerant tubing for split systems must be ASTM B280, cleaned, dehydrated, and sealed. Further, provide ASME B16.22 solder joint refrigerant fittings and adapters with silver brazing alloy solder and silver brazing alloy flux. During brazing operations bleed a small amount of dry oil-free nitrogen continuously through the refrigerant tubing. If required for connections to equipment, provide ASME B16.26 flared fittings.

Condenser Provide condenser circuit pre-piped with start-up and head pressure controls to maintain system operation at ambient temperatures down to 0°F.

Air-cooled Condenser Provide remote air-cooled condenser arranged for vertical air discharge. The direct-driven propeller fans must have factory balanced aluminum blades and fan guards. The coils must be assembled from seamless copper tubes with plate type aluminum fins. The coils, in the production process, must be pressure tested with compressed air 300 psig under water and verified to be leak-free. The air-cooled condensers casings and other components must be suitable for outdoor location and built from aluminum with manufacturer’s standard corrosion-resistant finish, or galvanized steel.

Condensing Unit Provide separate outdoor assembly designed to be used in conjunction with the indoor CRAC unit. Base ratings on the use of matched assemblies. Provide performance diagrams for units with capacities not certified by AHRI to verify the components of the air conditioning system satisfy the capacity requirement specified or indicated. Provide capacity, electrical characteristics and operating conditions as indicated. Condensing unit must provide not less than 10°F liquid subcooling at standard ratings.

Compressors For compressors over 20 tons, compressor speed must not exceed 3450 rpm. For systems over 10 tons provide automatic capacity reduction of at least 50% of rated capacity. Capacity reduction can be accomplished by cylinder unloading, use of multi- or variable speed compressors, use of multiple, but not more than four compressors, or a combination of the two methods. Units with cylinder unloading must start with capacity reduction devices in the unloaded position. Units with multiple compressors must have means to sequence starting of compressors. Provide compressors with devices to prevent short cycling when shut down by safety controls. Device must delay operation of compressor motor for at least 3 minutes but not more than 6 minutes. Provide a pumpdown cycle for units 20 tons and over. Provide reciprocating compressors with crankcase heaters in accordance with the manufacturer's recommendations. If compressors are paralleled, provide not less than two independent circuits.

Insulation All internal piping, fittings, valves, and appurtenances associated with the piping loop must be insulated during unit fabrication by the manufacturer. Insulation must be flexible elastomeric cellular secured with contact adhesive.

Unit Temperature and Pressure Control Cooling coil control valve must modulate to satisfy cooling coil leaving air temperature of 55°F (adjustable). Maximum allowable dead band is 5°F (adjustable).

Provide temperature and humidity sensors at both the unit return air inlet and supply air outlet.

A variable speed drive (VSD) must modulate fan speed to satisfy underfloor plenum differential air pressure setpoint of 0.02 inch w.g., minimum (adjustable). Each unit must have a differential pressure sensor, the pressure sensor settings must allow the VSD to operate between 40-100%. Unit controls must be capable of modulating fan speed to a minimum speed to prevent air from cycling through the unit due to underfloor static pressure greater than room level static pressure.

Units shall operate using individual pressure controls in the computer room. Each units must operate to maintain its own pressure setpoint.

Units must be capable of operating using zone pressure controls in the computer room. An average differential pressure reading for each zone shall be calculated, and units in each zone shall be capable to operate in teamwork mode to maintain pressure setpoint.

Control Panel Provide unit with a control panel with the following features:

Color touchscreen display viewable while the front panel is open or closed.

Menu-driven controls including user menus for active alarms, event log, graphic data, unit view/status overview (including the monitoring of room conditions, operational status in percentage of each function, date and time), total run hours, various sensors, display setup and service contacts.

Service menus, including setpoints, standby settings (lead/lag), timers/sleep mode, alarm setup, sensor calibration, maintenance/wellness settings, options setup, system/network setup, auxiliary boards and diagnostics/service mode.

Password required to make system changes. Coordinate changing default password from factory settings with the Government.

Factory installed emergency power off/remote shutdown connection.

All wiring over 50 VAC enclosed with a separate hinged cover inside the control panel to provide energized access to control wiring without exposing the higher voltage electrical components.

Space Temperature Control System Provide integral microprocessor control system with unit including electronic control center, control valves, sensors, wiring, and other appurtenances for workable system. Provide access panel or door in front of unit. Control system must be capable of accepting the following remote sensor connections at a minimum: temperature, pressure, and humidity.

Isolate electronic control center from conditioned airstream to allow service while system is in operation. Provide control sensors in unit for cooling and dehumidifying. High-voltage circuits in system must have individual leg overload protection. Control starters, contactors and relays by 24 volt control circuit.

Protect high-voltage circuit components by safety lock, dead-front panel. Mount nonautomatic, moldedcase circuit breaker in high-voltage section of electrical panel. Operating mechanism must prevent access to highvoltage electrical components until switched to "OFF" position.

Include the following control capabilities:

Capable of changing the setpoints and sensitivity of the space and humidity along with their low and high alarm points.

Logging capability of the last 10 alarms and run time.

Diagnostics Refrigerant compressor sequencing Alarm System All unit alarms must be annunciated through both audio and visual cues. System must monitor high and low space temperature, high and low space humidity, dirty filters, loss of power, loss of airflow, compressor high head pressure, and humidifier problems. Provide smoke sensor and underfloor water leak-detection cable loop matching the unit footprint. Provide field accessible local audible alarm with silence pushbutton. Provide push-to-test lamps or all-lamp test pushbutton. Provide local signal devices for remote audible and visual alarming capability for the above specified alarm conditions through BACnet or Modbus TCP/IP communication.

Alarm and Temperature Control Systems Requirements Provide the appropriate communication card or hardware to support connecting systems to the sites building automation system. The communication protocol must be BACnet or Modbus TCP/IP, in accordance with site requirements. The communication must occur without additional gateways or proprietary software. The unit must not have web servers or web interfaces installed or available to allow for connection to the building automation system or a separate network. The unit must have capacity for the addition of end-user readable and writable setpoints.

Modbus registers must be capable of providing the ability for the building automation system to read and write to all unit setpoint registers and read only to all other registers. At a minimum, provide 31 registers with the following points: Local Off Alarm, Loss of Airflow Alarm, Change Filters Alarm, High Temperature Alarm, Low Temperature Alarm, High Humidity Alarm, Low Humidity Alarm, Man Fan Overload Alarm, Smoke Detected Alarm, Loss of Water Alarm, Humidity Setpoint, Temperature Setpoint, Unit On/Off, Fan Motor Run Hours, High Humidity Alarm Setpoint, High Temperature Alarm Setpoint, Humidity Setpoint, Low Humidity Alarm Setpoint, Low Temperature Alarm Setpoint, Temperature Setpoint, Temperature Tolerance Setpoint, % Capacity Status, Cooling Status, Dehumidification Status, Humidity Status, Temperature Status, Unit Status.

Air Return and Delivery Orientation Provide units with downflow discharge, top return, draw-thru cooling coil, and which discharge air into a raised floor plenum with an acoustically-lined multiple turning vane elbow provided to direct the flow of air away from the back of the unit. Turning vane elbow must be assembled of 20 gauge galvanized steel and field-mounted and coordinate mounting with floorstand. Return air hood must be factory provided; CRAC height plus return air hood shall be 9 feet.

Floorstand Provide unit with elevating floorstand or jacks for freestanding installation on the main building floor. Floorstand or jacks must elevate the unit to the height of the new or existing raised computer floor and allow for leveling and locking at the desired height, and have adjustable legs with vibration isolation pads. Unit must be fully gasketed (rubber or neoprene) to prevent air leakage at the raised floor penetration.

Electrical Electrical Motors, Controllers, Contactors, and Disconnects Provide with the following respective pieces of equipment: motors, controllers, contactors, and disconnects conforming to all current national and local codes. Provide controllers and contactors with control circuits not to exceed unit input voltage or utility power voltage, and auxiliary contacts for use with controls provided. Motors must be variable-speed. When motors and equipment provided are larger than sizes indicated, the cost of providing additional electrical service and related work must be included under this section.

Disconnect Switch Provide factory-installed lockable disconnect switch to disrupt the flow of power to the unit.

Dual Power Source Provide factory-installed, automatic, dual power source connection. Dual power source connection must allow user to safely transfer power source from utility power to emergency backup source.

ISC Rating Equipment and installation must comply with NFPA 70 Articles 110.9 and 110.10. Provide ISC rating calculations. Equipment short circuit current rating must be adequate for maximum available fault current.

Variable Frequency Drive (VFD) Provide factory-installed VSD with noise filtering to modulate fan speed in response to room conditions.

ACCESSORIES

Nameplates Nameplates must be stainless steel and include at the minimum the following information:

Project name.

Customer order number Equipment designation Manufacturer’s name Manufacturer’s address Date manufactured Type and Style Model, catalog (if applicable) and serial numbers Framed Instructions Submit the following proposed documents at least 2 weeks prior to the start of related testing:

System layout diagrams that show Equipment layout, Piping, appurtenances, and valves, System wiring and controls, and Ductwork.

Condensed, typed operating instructions explaining Preventive maintenance procedures, Methods of checking the system for normal safe operation, and Procedures for safely starting and stopping the system.

Prior to performing acceptance testing, post approved framed instructions beside the diagrams under glass or in laminated plastic, where directed. Operating instructions must not fade and be secured to prevent easy removal or peeling.

Execution Installation CRAC Unit System Install each unit system including equipment, materials, installation, workmanship, fabrication, assembly, erection, examination, inspection, and testing, in accordance with ASME B31.1, ASME B31.5, NFPA 70, as modified and supplemented by the requirements of this section and the unit manufacturer's recommendations. Contractor is responsible to provide all necessary piping to make final supply and drain line connections and make the final piping connections.

Installation Instructions Provide a manufacturer's installation manual for each type of unit.

Field Quality Control Upon completion and before final acceptance of work, test each subsystem in service to demonstrate compliance with the Contract requirements, including field testing specified below. Adjust controls and balance systems prior to final acceptance of completed systems. Test controls through every cycle of operation. Test safety controls to demonstrate performance of required function. Correct defects in work provided by Contractor and repeat tests. Provide fuel, water, electricity, instruments, connecting devices, and personnel for tests. Flush and clean piping before placing in operation. Clean equipment, piping, strainers, and ducts. Prior to commencement of field testing, remove all filters and provide new filters.

Manufacturer Field Service Provide the services of a manufacturer's field test representative who is experienced in the installation, adjustment, and operation of the equipment specified. The representative must supervise the installation, adjustment, and testing of the equipment.

Adjusting and Cleaning Thoroughly clean surfaces of piping and equipment that have become covered with dirt, plaster, or other material during handling and installation before such surfaces are prepared for final finish painting or are enclosed within the building structure. Before final acceptance, clean mechanical equipment, including piping, ducting, and fixtures, and free from dirt, grease, and finger marks. Incorporate housekeeping for field work which leaves all furniture and equipment in the affected area free of generated dust and debris; and, all floor surfaces vacuum-swept clean.

Closeout Activities Training Provide a field training course for the operating and maintenance staff members as designated by the Contracting Officer. Conduct training for a total period of 8 hours of normal working time starting after the system is functionally complete but prior to final acceptance tests.

Field training must cover all of the items contained in the approved Operation and Maintenance Manuals, training plan, and training outline, as well as demonstrations of routine maintenance operations. Reference the O&M user manuals as a textbook. Provide training to the operations and maintenance staff following factory testing and startup, focused on the following training content:

System Overview Operation and maintenance of the equipment:

Startup Normal operations Shutdown Abnormal operation Recommended preventive maintenance to support the development of an equipment maintenance plan.

Alarms Troubleshooting Special features of equipment Inputting software program parameters Provide all training materials at least 6 weeks prior to the first class. Review and approval by DISA will be complete at least 3 weeks prior to the first class.

Notify the Contracting Officer at least 4 weeks prior to date of proposed conduction of the training course.

Notify the Contracting Officer of Training Completion. Submit sign-in sheet of all onsite personnel who attended and completed training.

Shop Drawings Upon completion, and before final acceptance of the work, submit a complete set of shop drawings. Provide shop drawings no smaller than A0 30 by 42 inches, reproducible with title block 8 by 4 inches similar to full size Contract drawings in .pdf and AutoCAD electronic format.

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